82 Maxim 650 (next step/another question)

From the guy that brought you these 2 threads:

http://www.xjbikes.com/Forums/viewtopic/t=5887.html
http://www.xjbikes.com/Forums/viewtopic/t=6052.html

So I am now at the point where I have set up the bike with a new fuse box and a new battery. Found out the previous owner didn't even have the ground connected so that helped Those together got the bike turning over but not firing (it won't start).

We checked for spark on the outside cylinders and they were sparking. We replaced the spark plugs anyway.

We completely removed the carburetors and dumped out all the old gas that was in them. We then got the gas out of the gas tank as best we could, put new gas in there and hooked everything back up thinking the new gas would be the trick. Still turning but not firing.

I'm assuming that its a gas problem, which is mainly what the manual points too at this point. Under "Fault Diagnosis" in the manual #5 it talks about no fuel to the carburettor and float chambers. How do you know if the float chambers at not working?

How do you fix a blocked fuel tap or filter blocked in the tank?

Then the manual talks about the floats in the cylinder sticking in the up position. Is there an easy diagnosis there?

Am I on the right track with the fuel or am I missing something major here. My battery is now dead from cranking over the bike, but i'll get that charged and probably try some starter fluid in the carbs next just to get it started.

Any advice is greatly appreciated.

 

I think you are one the right track but remember that when trouble shooting; fuel mimics fire. You need both to get it running so you have to find out if the fire is there first since it is the easiest one to confirm.
Tank: to check for fuel set the petcock to "res". Remove the fuel line and place or hold a suitable container under the petcock nipple where the fuel line was attached. Turn the petcock to "pri". If fuel comes out then the tank is clear. If fuel came out of the tank after removing the fuel line then the petcock is in need of repair. Fuel should only flow at the "pri" setting with the engine off. If fuel doesn't flow at the "pri" setting then the filter screen in the tank is clogged. Drain the tank and remove the petcock. When the petcock is out you will see the filter screen that extends up into the tank. Clean the outside and fuel should flow. If it is broken then gunk can get inside the petcock and it must be dismantled for cleaning. I usually remove the petcock switch and clean out from that side. Do not use compressed air since it may damage the rubber diaphraghm at the back of the petcock.
Floats: Check my photo gallery for an idea of how to setup the clear tube method of checking float height. This is the easiest way to be sure the floats are working properly. The float bowl drain screws need to be free to check the floats and if they are stuck then I highly recommend removing the carbs and doing a good cleaning. It is also easiest to check float operation with the carbs off the bike. Your problem most likely will be dirty carbs with clogged idle jets and passages. Properly operating floats will not allow the bike to run per se, they can be working fine and the bike will not start if the idle jets are clogged.
Simplest way to check if fuel is getting to the sparkplugs it to crank the bike with the throttle open and choke on. Then pull the sparkplugs and look and smell for fuel. If you don't find it the it ain't getting there.

 

BlueMaxim thanks so much for your advice. A couple of questions:

Your pictures are awesome, i was wondering how much i can dig into the floats before I run into gaskets and then have more to replace then i want to?

I can hear the floats "moving" when i shake the carbs, at least i think thats what i'm hearing. Should I use carb cleaner and just spay a ton in there or is dismantling the whole thing necessary?

To your last section we did take a couple plugs out and hit the starter, air was being pushed pretty good and it did smell like gas so thats good and bad considering it wasn't firing.

I may need someone to explain where the idle jets are and how to unclog them if they need it.

Thanks again.

 

Rick is the master jedi of carbs, look for his instructions, it worked for me. For carbs, guilty until proven innocent is usually true, I would clean them thoroughly, dismantle. Rick's thread will help you do it right like it helped me.